Efficient techniques for reducing error latency in on-line periodic BIST

With transient and intermittent operational faults becoming a dominant failure mode in modern digital systems, the deployment of on-line test technology is becoming a major design objective. On-line periodic BIST is a testing method for the detection of operational faults in digital systems. The method applies a near-minimal deterministic test sequence periodically to the circuit under test and checks the circuit responses to detect the existence of operational faults. On-line periodic BIST is characterized by full error coverage, bounded error latency, moderate space and time redundancy. In this paper, we present various techniques to minimize the error latency without sacrificing the full error coverage. These techniques are primarily based on the reordering the test vectors or the selective repetition of test vectors. Our analytical and preliminary experimental results demonstrate that our techniques lead to a significant reduction in the error latency.